U.S. Pat. No. 5,969,735 discloses a franking machine provided with an ink supply device which comprises an intermediate reservoir for regulating the level of ink delivered to the ejection nozzles of the printing module from a principal ink reservoir.
However, such a supply device appears complex and poorly adapted to the printing of postal indicia of which the slogan is of a colour different from that used for the postage printing ink. In effect, as this device continuously supplies the injection nozzles, it is necessary to provide as many devices as there are colours to be used, of which at least one for supplying postage printing ink (generally of a very specific colour), this resulting in a relatively expensive machine.
In addition, any problem arising at the level of the intermediate reservoir or of the principal ink reservoir automatically prohibits any fresh print.
It is an object of the present invention to overcome the afore-mentioned drawbacks by proposing a particularly high-performance franking machine which is nonetheless simple to use.